The ITLibMediaEntity class describes a media entity which can be a media item such as an audio track (see ITLibMediaItem) or a playlist (see ITLibPlaylist). Each media entity has a persistent unique ID assigned by iTunes and a set of properties.

The ITLibMediaItem class describes a media item (a track) in the iTunes library such as a song, a video, or a podcast. Like all media entities, each media item has a unique identifier and a set of properties.

The ITLibPlaylist class describes a playlist in the iTunes library. A playlist is a collection of media items (tracks). Playlists may be created and organized manually by the user or automatically generated by iTunes. Playlists are modeled as media entities. Each contains a unique identifier and a set of properties. Playlists may form a hierarchical structure. In those cases, the parentID property of ITLibPlaylist returns the persistent ID of the parent playlist.

A class that serves as the entry point to the iTunesLibrary framework. The properties and methods of ITLibrary may be used to retrieve media items (tracks) and playlists from the user’s iTunes library. ITLibrary also provides methods for extracting artwork from a media file that may or may not be in the iTunes library. This functionality is provided to sandboxed and non-sandboxed applications wanting to reuse iTunes' ability to extract artwork.